Turning-in of weft thread ends is known as a technique for creating a selvedge and is achieved by either using a needle which engages the weft thread end and positions it within the shed prior to beat-up or using several jet nozzles as demonstrated in U.K. Pat. No. 543,398 for blowing the weft thread end into the shed prior to beat-up. Both of these modes of operation have drawbacks and are unsuitable particularly at high pick rates.
For instance, the first mode of operation requires precision in construction and setting up in order to ensure that the needle correctly engages with the weft thread end. Additionally, since the needle penetrates into the shed it must be removed before beat-up can be completed. Accordingly, immediately before beat-up the weft thread end is unsupported and so is unable to relax thereby creating a loose selvedge which is unsatisfactory.
With regard to the second mode of operation the end of the weft thread is inserted by stream of air flowing from jet nozzles and has the tendency to snag against the warp threads. This tendency obviously increases if the weft thread and/or warp threads are of a hairy character. Accordingly, correct turning-in is not consistently assured and so can result in an irregular selvedge. Additionally, use of several jet nozzles necessitates a high consumption of pressurized air.